It is known to provide a separating net between a cargo or storage space in an automotive vehicle and a passenger or driver's compartment. Such systems usually wind up the web-shaped member, usually a mesh or net, on a lower rod which can be received in a housing. The upper edge of the net is provided with an upper holding rod which can be engaged in brackets or holders at the roof of the vehicle so that the net can be pulled out of the housing and unrolled from the lower rod like a window shade.
The lower rod is a winding shaft onto which the web is wound and may be under spring action to automatically wind up the net and store a winding force when the net is withdrawn. The net can be received in the housing in some other compressed form as well.
Generally the net bridges the opening which may remain between the upper part of the vehicle back rests or between some other seating part of the vehicle and the vehicle roof.
It should be noted that the invention here relates not only to automotive vehicle nets of the type described but also to covers for the storage compartment of a vehicle and indeed wherever a rod or bar is connected to a web in a vehicle and is releasably anchored in brackets on opposite sides of the vehicle.
As has been indicated, the separating net for a motor vehicle serves primarily in the case of sharp deceleration of the vehicle, especially a rapid stopping in the case of a crash, to prevent objects in the storage compartment of the vehicle from flying into the passenger compartment. The upper rod is in that case inserted into the brackets on opposite sides of the vehicle adjacent the roof. For that purpose, the rod has fastening elements at its ends, especially mushroom-shaped or other enlargements, for engagement in receiving grooves of the brackets.
In case of a crash the forces which are produced are numerous and it is therefore important that the holding rod not be sharply bent or broken if the separating net is to retain its safety function. It is also important that the entire energy which may be applied to the rod in the case of a crash not be transmitted to the brackets. A variety of tests have been made heretofore in order to develop a satisfactory energy-absorbing system for a separating net. However, there is a significant problem in that the rod itself is usually a tubular hollow body in which the fastening elements at the ends may be axially shiftable and thus has little available space in which energy absorbing elements can be arranged.
In German Patent Document DE 40 10 209 A1 for example, an energy absorbing system has been proposed for a holding rod for a separating net which utilizes a constriction in the tubular body and an inwardly widening conical end piece which deforms corrugation-like indentations of the tube in the case of a crash. Difficulties have been encountered with this system as to the fabrication and mounting tolerances of the corrugation-like indentations since the exact deformation forces and their transmission depend directly upon such tolerances.
Another problem is the drawback of deforming the holding tube of the rod itself, i.e. the tubular body, since that introduces the danger of excessive stressing of the tube which can result in breakage of the tube in the case of a crash because of the weakening of the tube by reduction of its bending or bucket resistance.
These problems have been recognized in European Patent Document EP 0 649 778 B1 which proposes an improvement in the energy dissipating arrangement by providing a separate deformation body which is either a component of an insert or a separate cylindrical tube according to the embodiment of FIGS. 8 and 9 of this patent document. The holder has here on its inner end two diametrically opposite radial projections which result from indentation of the shaft. The part projecting over the outer surface of the shaft has a generally semicircular shape. The two radial projections form an abutment body which prevents the holder elements from falling out of the rod. In the case of a crash the radial projections increasingly are forced through the deformation body and deform the latter. The deformation body is braced in the system of this patent document against a separate element in the form of a steel ring. The deformation of the deformation body is in the nature of an embedding of the radial projections in the interior of that body.